ABS Home

Census home > Data quality > Fact sheets

Grandparent families

In the Census, families are identified and classified in terms of the relationship that exists between a single family reference person and each other member of the family. Grandparent families are recognised where there is a grandparent-grandchild relationship in a family and no parent-child relationship.

In the 2011 Census, three new grandparent/grandchild variables have been created to enable grandparent families to be identified more easily. These variables are not included in any Census data products but are used to service customised data requests on grandparent families (see Custom Data Services). These are in addition to standard family and relationship variables and may be used in combination with other person, family and dwelling variables.

Standard variables Grandparent variables
RLHP (Relationship in Houshold) RLGP (Relationship in Household, including grandchildren)
FMCF (Family Composition) FMGF (Grandparent Families)
CTPP (Child Type) CTGP (Child Type, including grandchildren)


Both variables describe relationship of each person in a family to the family reference person or, where a person is not part of a family, that person's relationship to the household reference person. RLGP classifies grandchildren, including those aged 15 years and over, as a 'child', whereas RLHP classifies persons aged 15 and over as 'other relative'.


Both variables classify families into different family types, depending on the composition of the family. When classifying families into different types, information about temporarily absent family members is used. The focus of the FMGF classification is on grandparent families.


Both variables identify parent-child relationships within families. CTGP recognises grandparent-grandchild relationships as parent-child relationships, regardless of the age of the grandchild.

When using standard variables, a person who is aged 15 years or more and has the relationship of ‘grandchild’ is treated as an ‘other relative’. That is, if there is a sole grandparent in the family, the family is coded as an ‘other family’. A grandparent couple would be coded as a ‘couple family with no children and with relatives’.

When using grandparent variables, this person is treated as a type of ‘child’. A sole grandparent is classified as a ‘lone parent’ and a family with a grandparent couple is classified as a ‘couple family with children’. The grandchild would have a relationship of 'dependent student' or 'non-dependent child' rather than ‘other relative’.

Due to these differences in definitions, it is very important that the ‘grandparent’ variables are not mixed with the standard variables, as this could result in incorrect data.

Issues to consider

Users should note that grandparent-grandchild relationships are constructed for the purposes of family coding in order to create a statistical family. It may not be representative of who provides care, for example a grandparent caring for their grandchild or vice versa. It is very important that users do not make assumptions about grandparent families, especially in relation to care. A 20 year old grandchild who lives with her grandmother may be a full-time student and is dependent on her grandmother for care. Alternatively, she may have moved in with her grandmother specifically to take care of her.

The limited information can also result in incorrectly identifying some children as grandchildren in the family and incorrectly identifying relationships as grandparent-grandchild relationships. For example, if a parent is temporarily absent from the family, and their relationship reported does not confirm their relationship to their child, that parent-child relationship cannot be coded. This can result in a small number of children being reported as grandchildren when a parent is simply absent on Census Night.

Census form question

Question 5 on the Census Household Form asks about the relationship of each person to Person 1, the family reference person. Question 53 asks the same question for any usual resident who is absent. Where 'Other relationship' is indicated, examples of possible responses are given, including 'granddaughter'.

Question 5 as it appeared on the 2011 Census Household Form

A text only version of this question is also available.

Fact sheets

  • Grandparent families


Enumeration procedures

2006 fact sheets